After you have selected your default email client, you will always land in the selected email client whenever and wherever you click within the Mac. You can always repeat the above steps to change your email clients or restoring the default Mail app.

I have installed version 15.3 of the newly released Outlook.

Most of the time I am promted to send an email by another program (like from one of my Browsers) it opens and wants to use Apple Mail.

I want it to use Outlook as the default mail program

So I go to Outlook preferences open

General and then

Check the box to make outlook the Default Mail program

and close it.

Well as soon as I close that box the check goes away and Outlook is not my default mail program.

How can I get the check to stay and make Outlook my default Email program

Changing Default Mail Client Mac

Osx Change Default Program

Thanks!!!